A New DNA Technique Led to the Capture of Some of California’s Most Notorious Criminals. Could it Free an Innocent Man?

California law enforcement have closed a number of cold cases in recent years using what a front-page story in yesterday’s Los Angeles Times describes as a “controversial” DNA testing technique that allows investigators to identify suspects based on DNA that matches their immediate male relatives. One of the cases solved using this technique includes that of the notorious “Grim Sleeper,” the nickname for serial killer Lonnie Franklin Jr., who may have killed 25 women over the span of two decades.

According to the Times report, even skeptics who were wary of possible privacy violations and racially disparate outcomes have begun to rethink their opposition in light of the impressive track record of this relatively new method:

Nabbing Franklin changed things for now-UCLA Law School Dean Jennifer Mnookin, who once condemned using DNA to find suspects by searching for relatives. Mnookin argued that the method invades privacy rights and is racially discriminatory because African Americans and Latinos are disproportionately represented in DNA databases.

Although she still worries about the racial disparity, she said her view shifted after seeing the effect on big cases, such as Franklin’s, and how infrequently the technology is used.

As it happens, this particular type of DNA testing is a key element of a case Reason TV covered in a three-part video series. The case concerns an Orange County man named Kenneth Clair, whom a jury sentenced to death in 1987 for the murder and assault of a 25-year-old woman named Linda Faye Rodgers.

Decades later, a private eye working for Clair uncovered the fact that the Orange County District Attorney’s office had tested male DNA found on the victim’s genitals. The DNA did not match Clair and, furthermore, it did match someone else in a criminal database. Upon learning this information, Clair’s team asked for the county to release the name of the match, but the county refused, citing privacy concerns and pointing out that the matching individual would have been too young to have committed the crime. But the fact that the database hit didn’t lead to a plausible suspect doesn’t rule out the possibility that an older male relative, such as a father or uncle, might be the perpetrator. By refusing to release the name of the match, the county is foreclosing possible alternative investigatory avenues. Indeed, this is precisely the situation that led police to capture the Grim Sleeper, according to the Times:

After getting a partial DNA hit to his son in 2010, authorities charged Franklin with killing nine women and a teenage girl. He was convicted earlier this year and sentenced to death.

The DA’s office refuses to speak on the record about why they withheld the very fact that they ran the DNA test or why they continue to hold back the name of the DNA match in the Clair case, but they have this to say in a press release on the matter:

The fact that male DNA [the Y-STR haplotype] was detected in a swab of the victim’s vagina is no indication she was raped at the time of her murder, or even that she had intercourse at the time of the murder. The swabs tested negative for semen at the time of trial. (Trial RT 1591.) Thus, any male DNA [the Y-STR haplotype] in the victim’s vagina was either deposited well before her murder, or was the result of contamination of the sample. If in fact the victim had had sexual contact with some male relative of the individual whose Y DNA apparently matches the Y DNA found in the vaginal swab, discovery of that male relative would not in any way diminish the evidence against Clair in this case. It would have no tendency to prove that someone other than Clair killed Linda Rodgers. [bolding added]

It’s true enough that if the male DNA was simply a result of contamination by a member of the forensics team, it would have no bearing on Clair’s innocence or guilt. But by refusing to release this crucial piece of information, the DA is asking Clair’s team—and the public—to simply trust the integrity of their investigation in a case that’s riddled with problems.